Studies on thermoset blend of bismaleimide having multiple swivel groups and biscyanate ester

Abstract

The materials 2,2-bis [4-(4-maleimidophenoxy phenyl)] propane (BMIX) and bisphenol-A based cyanate ester (BCY) were synthesized. The monomers BMIX and BCY were physically blended (BMCY) in 1:1 mol ratio. The materials BMIX, BCY and BMCY were thermally polymerized and the structural characterisation of the materials was done using Fourier transform infrared spectrophotometer (FTIR). The curing characteristics of BMIX, BCY and its blend (BMCY) were investigated using differential scanning calorimeter (DSC). The blend BMCY shows considerable differences in the thermal curing behaviour as evidenced by the DSC studies. Blending BCY with BMIX drastically reduces the melting temperature, curing onset temperature and the amount of heat liberated during thermal curing. The thermal stabilities of the crosslinked network polymers (PBMIX, PBCY and PBMCY) were investigated using thermogravimetric analyser (TGA). Detailed TGA studies indicated that the PBMCY shows better thermal stability than the PBMIX and PBCY. The DSC and TG curves indirectly hint about the possible reaction between BMIX and BCY during thermal curing. Woven glass fibre reinforced laminates were prepared using BMIX, BCY and BMCY by solution impregnation followed by drying and compression moulding. The glass laminate having BMCY as the matrix resin showed much better mechanical property (tensile strength) compared to the laminate made using BMIX as the matrix resin.